Reduced graphene oxide-induced crystallization of CuPc interfacial layer for high performance of perovskite photodetectors

Taoyu Zou; Jianqi Zhang; Shuyi Huang; Chenning Liu; Renzheng Qiu; Xiaozhi Wang; Wei Wu; Hai Wang; Zhixiang Wei; Qing Dai; Chuan Liu; Shengdong Zhang; Hang Zhou

doi:10.1039/c8ra08864k

Reduced graphene oxide-induced crystallization of CuPc interfacial layer for high performance of perovskite photodetectors

RSC Adv. 2019 Jan 29;9(7):3800-3808. doi: 10.1039/c8ra08864k. eCollection 2019 Jan 25.

Authors

Taoyu Zou¹, Jianqi Zhang², Shuyi Huang³, Chenning Liu⁴, Renzheng Qiu¹, Xiaozhi Wang³, Wei Wu⁵, Hai Wang⁶, Zhixiang Wei², Qing Dai², Chuan Liu⁴, Shengdong Zhang¹, Hang Zhou¹

Affiliations

¹ School of Electronic and Computer Engineering, Peking University Shenzhen Graduate School Shenzhen 518055 China zhouh81@pkusz.edu.cn.
² National Center for Nanoscience & Technology Beijing 100190 PR China.
³ Key Lab of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, College of Information Science and Electronic Engineering, Zhejiang University Hangzhou 310027 China.
⁴ State Key Laboratory of Optoelectronic Materials and Technologies, School of Electronics and Information Technology, Sun Yat-Sen University Guangzhou 510006 China.
⁵ London Centre for Nanotechnology, University College London Gower Street London WC1E 6BT UK.
⁶ Key Laboratory of Yunnan Provincial Higher Education Institutions for Organic Optoelectronic Materials and Devices, Kunming University Kunming 650214 China.

Abstract

Perovskite-based photodetectors have great potential in light-signal conversion; the suppression of the dark current is regarded as one of the main concerns within the academic research communities to achieve a high-performance photodetector. Interfacial engineering in the transport layer is considered as one of the most essential methods for enhancement of perovskite photodetectors. Here, a nanocomposite thin film of tetra-sulfonated copper phthalocyanines and reduced graphene oxide (TS-CuPc/rGO) was investigated as the interfacial layer in perovskite-based photodetectors. Photodetectors with the TS-CuPc/rGO thin film as the interfacial layer exhibited a low dark current density of 2.2 × 10^-8 A cm^-2 at bias of -0.1 V as well as high responsivity and detectivity of ∼357 mA W^-1 and ∼4.2 × 10¹² jones, respectively; moreover, we observed an ON/OFF ratio of 7.33 × 10³ to 520 nm light with an intensity of ∼0.077 mW cm^-2. Our study revealed that with rGO additives, TS-CuPc molecules were favorable for the formation of an edge-on stacking film with high crystallinity. The rGO-induced crystalline TS-CuPc thin film with lower crystallographic defects effectively reduced the carrier recombination rate at the interfaces, leading to a suppressed dark current and enhanced photocurrent in the photodetector device, when compared to the less crystalline TS-CuPc layer.